Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Operating activities:
Net loss	$ (22,262)	$ (28,285)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	144	254
Loss on disposal of property and equipment	39
Noncash interest expense	164	160
Financing derivative	252
Amortization of premium on marketable securities	130	377
Stock based compensation expense	913	1,484
Modification of stock options related to executive retirement	389
Modification of stock options related to restructuring activities	479
Changes in operating assets and liabilities:
Prepaid expenses and other assets	940	(6)
Accounts payable	(804)	(2,277)
Accrued compensation	(418)	289
Accrued research and clinical liabilities	(1,079)	(1,324)
Other liabilities	53	82
Deferred rent	(9)	169
Net cash used in operating activities	(21,069)	(29,077)
Investing activities:
Purchase of marketable securities	(3,703)	(49,902)
Proceeds from maturities of marketable securities	33,371	34,190
Purchases of property and equipment	(136)	(317)
Proceeds from disposal of property and equipment	1
Change in restricted cash	7	12
Net cash provided by (used in) investing activities	29,540	(16,017)
Financing activities:
Increase in restricted cash for notes payable	(8,291)
Proceeds from issuances of notes payable		5,000
Proceeds from issuance of common stock		60
Principal payments under notes payable	(3,452)	(2,916)
Settlement of fractional shares upon reverse stock split	(1)
Net cash (used in) provided by financing activities	(11,744)	2,144
Net decrease in cash and cash equivalents	(3,273)	(42,950)
Cash and cash equivalents, beginning of period	10,923	54,220
Cash and cash equivalents, end of period	7,650	11,270
Supplemental cash flow disclosure:
Cash paid for interest	564	725
Supplemental disclosure of non-cash financing activities:
Principal payments under notes payable from restricted cash	$ 432